Retractable blade knife



FIG. 1 is a side elevational view of the retractable blade knife showing our new design;

FIG. 2 is an opposite side elevational view thereof;

FIG. 3 is a side elevational view thereof with the blade shown extended;

FIG. 4 is an opposite side elevational view thereof with the blade shown extended;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a top, rear perspective view thereof;

FIG. 8 is a bottom, rear perspective view thereof. 

The ornamental design for a retractable blade knife, as shown and described. 